Healing of corneal epithelial erosions or ulcer constitute a major unsolved problem in clinical ophthalmology. The effect of epidermal growth factor (EGF) in promoting repair of the corneal epithelium damaged under a variety of conditions will comprise a major aspect of this study. Furthermore, a systematic evaluation of EGF for toxicity and antigenicity in animals will be conducted. Although not a part of this proposal, these studies may lead to a large clinical trial of EGF in humans with epithelial defects or chronic ulcerations of the cornea.